Modifying a parametrically defined model with an explicit modeler

ABSTRACT

A method, system, apparatus, article of manufacture, and computer readable storage medium provide the ability to manage modifications to a solid model between different modeling applications. An original model created using a parametrically-based modeler is obtained. A modified version of the original model that was edited using a history-free modeler is obtained. The original model and the modified version are analyzed to determine differences between them. Based on the differences, a set of parametric-based treatments are determined that, when performed on the original model, affect changes that produce a parametrically-driven version that geometrically matches the modified version. One or more of the treatments are individually selected and applied to produce the parametrically-driven version.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims the benefit under 35 U.S.C. Section 119(e) ofthe following co-pending and commonly-assigned U.S. provisional patentapplication(s), which is/are incorporated by reference herein:

Provisional Application Ser. No. 61/389,097, filed Oct. 1, 2010, byUdaya Gunasena, Alan C. Cramer, Rahul Vora, Jeff Strater, and Kevin J.Schneider, entitled “MODIFYING A PARAMETRICALLY DEFINED MODEL WITH ANEXPLICIT MODELER,”

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates generally to parametric modeling, and inparticular, to a method, apparatus, and article of manufacture formodifying a parametrically defined model with an explicit modeler.

2. Description of the Related Art

Models may be created using parametric based modeling programs thatmaintain a history of operations used to create the model. Otherdirect/explicit modelers (i.e., modelers that do not maintain a history)may be used to edit/modify a model originally created using a parametricmodeler. However, when such an edited model is opened back in aparametric modeler, if the geometry was edited, the feature history islost. Such problems may be better understood with a description of priorart modelers and model editing.

With the evolution of software, designers have changed their fundamentalapproach to graphics design, moving from two-dimensional (2D) drawingsystems to three-dimensional (3D) solid modeling systems. New softwaremakes solid modeling technology available and affordable to virtuallyanyone.

Solid modeling is a technique that allows designers to createdimensionally accurate 3D solid models in a 3D space represented withina computer, rather than traditional 2D drawings. 3D solid models includesignificantly more engineering data than 2D drawings, including thevolume, bounding surfaces, and edges of a design.

With the graphics capabilities of today's computers, these 3D solidmodels may be viewed and manipulated on a monitor. In addition toproviding better visualization, 3D solid models may be used toautomatically produce 2D drawing views, and can be shared withmanufacturing applications and the like.

Some 3D solid modeling systems generate parametric feature-based models.A parametric feature-based model is comprised of intelligent features,such as holes, fillets, chamfers, etc. The geometry of the parametricfeature-based model is defined by underlying mathematical relationships(i.e., parameters) rather than by simple unrelated dimensions, whichmakes them easier to modify. These systems preserve design intent andmanage it after every change to the model.

Moreover, these features automatically change as the model is changed.The system computes any related changes to parts of the model that aredependent on a parameter, and automatically updates the entire modelwhen the parameter is changed. Accordingly, the entire 3D model willupdate based on a new shape of a modified feature. In this regard,features in the model are recomputed based on modifications toparameters affecting such features. For example, a through-hole willalways completely go through a specified part, even if the part'sdimensions are changed to be bigger than the hole.

In parametric modelers, a history of how a particular object or body iscreated is created and maintained. In other words, the series of stepsthat were used to create the object/body is maintained in a history.Such steps can be modified at any point. However, to modify a particularstep, the user is often required to search through a long history tofind the step to modify.

In addition to parametric based modelers, 3D models may also becreated/edited in a history-free (also known as “direct” or “explicit”)based modeler. In an explicit modeler, no history is maintained and thefeature/model is not recomputed based on a particular face/bodymodification. The advantage to the explicit modeler is that the userdoes not need to find a specific step in order to modify a body. If aface needs to be changed, the user can simply select and move the face.If such a task was to be accomplished in a parametric modeler, with acomplex model, it might take a very long time to find the spot in thehistory in order to modify it. Moreover, there may be constraints thatconflict with the edit or there may be “downstream” feature failures.Such issues can make the edit of a parametric model difficult.

Often times, one or more users may utilize a combination of bothparametric modelers and explicit modelers to accomplish a given task.For example, an original 3D model may be created in a parametric modeland then edited using an explicit modeler (e.g., the parametricallycreated model is opened in an explicit modeling application). As afurther example, downstream users that are not experts with a parametricmodeling program (e.g., packaging personnel, manufacturing personnel,analyst, quality assurance personnel, etc.) may need to edit aparametric model provided by a design engineer (e.g., if the product asdesigned will not fit in the packaging, or the product cannot bemanufactured with a fillet in a certain configuration, etc.). Suchdownstream users may utilize an explicit modeler to perform the desirededits.

Once edits are made in an explicit modeler, the design engineer may wantto incorporate the changes from the explicit model into the originalparametric based model. However, the edits from the explicit modeler mayhave removed various features from the history. Consequently, prior artembodiments fail to maintain a history and fail to provide the abilityto interchangeably use an explicit modeler and parametric modeler.Further, even if the parametric model attempted to create new historyfeatures that recreate/generates the same shape/body/edit from theexplicit modeler, it can be difficult/impossible to find such a set ofedits to the parametric model.

In view of the above, what is needed is a mechanism that provides theability to perform edits in an explicit modeler while accuratelyreflecting such edits by updating the history in a parametric modeler.

SUMMARY OF THE INVENTION

There have always been a division between the different types ofmodelers—explicit/history-free modelers and parametric based modelers.Users have traditionally not been able to easily move from one model tothe other and back because of the inherent nature of the two differentmodelers. Embodiments of the invention seek to provide users a methodfor going back and forth between the two different modelers and join theparadigms.

Embodiments of the invention solve the problem of tracking changes thatare made by an explicit modeler (e.g., to a model initially created in aparametric modeler or to a model created in/by the explicit modeler),back to an original parametric model. A tool is used to display thedifferences between the models (or if the model was created in anexplicit modeler, a proposed set of parametric based features) in aformat that is natural for the user of a parametric history basedcomputer aided design application. The tool presents the differences insmaller, specific changes, and provides a set of options of edits thatwill affect the change.

BRIEF DESCRIPTION OF THE DRAWINGS

Referring now to the drawings in which like reference numbers representcorresponding parts throughout:

FIG. 1 is an exemplary hardware and software environment used toimplement one or more embodiments of the invention;

FIG. 2 schematically illustrates a typical distributed computer systemusing a network to connect client computers to server computers inaccordance with one or more embodiments of the invention;

FIG. 3 is a block diagram that illustrates the components of a graphicscomputer program according to the preferred embodiment of the presentinvention;

FIG. 4A illustrates an exemplary parametric, feature based, associativemodel that has been created in a parametric modeler in accordance withone or more embodiments of the invention;

FIG. 4B illustrates the same model of FIG. 4A after being modified in ahistory-free modeler in accordance with one or more embodiments of theinvention;

FIG. 4C illustrates the parametric model of FIG. 4A and the history freemodel of FIG. 4B with a list of feature centric changes or “treatments”illustrated in a Change Manager window in accordance with one or moreembodiments of the invention; and

FIG. 5 is a flowchart illustrating the logical flow for managingmodifications to a solid between different modeling applications inaccordance with one or more embodiments of the invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

In the following description, reference is made to the accompanyingdrawings which form a part hereof, and which is shown, by way ofillustration, several embodiments of the present invention. It isunderstood that other embodiments may be utilized and structural changesmay be made without departing from the scope of the present invention.

Overview

One or more embodiments of the invention provide a “Change Manager” aspart of a graphics program that allows a user to modify a parametricallydefined body with an explicit modeler and incorporate such changes intothe original parametric model. To incorporate the changes made in anexplicit modeler, the user goes back to using a parametric modeler andopens the model that was modified in the explicit modeler. The ChangeManager performs an analysis of the changes based on the modifiedversion and the original parametric model, and modifies the history toreflect the changes. Such a process is advantageous over the prior artwhich required the user to manually perform changes in the parametricmodeler until the changes were matched in the parametric step.Accordingly, the Change Manager enhances the user's ability to movebetween modelers and make changes using the modeler of their choosing asthe situation dictates.

Hardware Environment

FIG. 1 is an exemplary hardware and software environment 100 used toimplement one or more embodiments of the invention. The hardware andsoftware environment includes a computer 102 and may includeperipherals. Computer 102 may be a user/client computer, servercomputer, or may be a database computer. The computer 102 comprises ageneral purpose hardware processor 104A and/or a special purposehardware processor 104B (hereinafter alternatively collectively referredto as processor 104) and a memory 106, such as random access memory(RAM). The computer 102 may be coupled to other devices, includinginput/output (I/O) devices such as a keyboard 114, a cursor controldevice 116 (e.g., a mouse, a pointing device, pen and tablet, etc.) anda printer 128. In one or more embodiments, computer 102 may be coupledto a media viewing/listening device 132 (e.g., an MP3 player, iPod™,Nook™, portable digital video player, cellular device, personal digitalassistant, etc.).

In one embodiment, the computer 102 operates by the general purposeprocessor 104A performing instructions defined by the computer program110 under control of an operating system 108. The computer program 110and/or the operating system 108 may be stored in the memory 106 and mayinterface with the user and/or other devices to accept input andcommands and, based on such input and commands and the instructionsdefined by the computer program 110 and operating system 108 to provideoutput and results. The computer program 110 preferably comprises aparametric feature-based solid modeling system or an explicit modelingsystem, although other graphics/solid modeling programs 110 could beused as well.

Output/results may be presented on the display 122 or provided toanother device for presentation or further processing or action. In oneembodiment, the display 122 comprises a liquid crystal display (LCD)having a plurality of separately addressable liquid crystals. Eachliquid crystal of the display 122 changes to an opaque or translucentstate to form a part of the image on the display in response to the dataor information generated by the processor 104 from the application ofthe instructions of the computer program 110 and/or operating system 108to the input and commands. The image may be provided through a graphicaluser interface (GUI) module 118A. Although the GUI module 118A isdepicted as a separate module, the instructions performing the GUIfunctions can be resident or distributed in the operating system 108,the computer program 110, or implemented with special purpose memory andprocessors.

Some or all of the operations performed by the computer 102 according tothe computer program 110 instructions may be implemented in a specialpurpose processor 104B. In this embodiment, the some or all of thecomputer program 110 instructions may be implemented via firmwareinstructions stored in a read only memory (ROM), a programmable readonly memory (PROM) or flash memory within the special purpose processor104B or in memory 106. The special purpose processor 104B may also behardwired through circuit design to perform some or all of theoperations to implement the present invention. Further, the specialpurpose processor 104B may be a hybrid processor, which includesdedicated circuitry for performing a subset of functions, and othercircuits for performing more general functions such as responding tocomputer program instructions. In one embodiment, the special purposeprocessor is an application specific integrated circuit (ASIC).

The computer 102 may also implement a compiler 112 which allows anapplication program 110 written in a programming language such as COBOL,Pascal, C++, FORTRAN, or other language to be translated into processor104 readable code. After completion, the application or computer program110 accesses and manipulates data accepted from I/O devices and storedin the memory 106 of the computer 102 using the relationships and logicthat was generated using the compiler 112.

The computer 102 also optionally comprises an external communicationdevice such as a modem, satellite link, Ethernet card, or other devicefor accepting input from and providing output to other computers 102.

In one embodiment, instructions implementing the operating system 108,the computer program 110, and the compiler 112 are tangibly embodied ina computer-readable medium, e.g., data storage device 120, which couldinclude one or more fixed or removable data storage devices, such as azip drive, floppy disc drive 124, hard drive, CD-ROM drive, tape drive,etc. Further, the operating system 108 and the computer program 110 arecomprised of computer program instructions which, when accessed, readand executed by the computer 102, causes the computer 102 to perform thesteps necessary to implement and/or use the present invention or to loadthe program of instructions into a memory, thus creating a specialpurpose data structure causing the computer to operate as a speciallyprogrammed computer executing the method steps described herein.Computer program 110 and/or operating instructions may also be tangiblyembodied in memory 106 and/or data communications devices 130, therebymaking a computer program product or article of manufacture according tothe invention. As such, the terms “article of manufacture,” “programstorage device” and “computer program product” as used herein areintended to encompass a computer program accessible from any computerreadable device or media.

Of course, those skilled in the art will recognize that any combinationof the above components, or any number of different components,peripherals, and other devices, may be used with the computer 102.

Although the term “user computer” or “client computer” is referred toherein, it is understood that a user computer 102 may include portabledevices such as cell phones, notebook computers, pocket computers, orany other device with suitable processing, communication, andinput/output capability.

FIG. 2 schematically illustrates a typical distributed computer system200 using a network 202 to connect client computers 102 to servercomputers 206. A typical combination of resources may include a network202 comprising the Internet, LANs (local area networks), WANs (wide areanetworks), SNA (systems network architecture) networks, or the like,clients 102 that are personal computers or workstations, and servers 206that are personal computers, workstations, minicomputers, or mainframes(as set forth in FIG. 1).

A network 202 such as the Internet connects clients 102 to servercomputers 206. Network 202 may utilize Ethernet, coaxial cable, wirelesscommunications, radio frequency (RF), etc. to connect and provide thecommunication between clients 102 and servers 206. Clients 102 mayexecute a client application or web browser and communicate with servercomputers 206 executing web servers 210. Such a web browser is typicallya program such as MICROSOFT INTERNET EXPLORER™, MOZILLA FIREFOX™,OPERA™, APPLE SAFARI™, etc. Further, the software executing on clients102 may be downloaded from server computer 206 to client computers 102and installed as a plug in or ACTIVEX™ control of a web browser.Accordingly, clients 102 may utilize ACTIVEX™ components/componentobject model (COM) or distributed COM (DCOM) components to provide auser interface on a display of client 102. The web server 210 istypically a program such as MICROSOFT'S INTERNENT INFORMATION SERVER™.

Web server 210 may host an Active Server Page (ASP) or Internet ServerApplication Programming Interface (ISAPI) application 212, which may beexecuting scripts. The scripts invoke objects that execute businesslogic (referred to as business objects). The business objects thenmanipulate data in database 216 through a database management system(DBMS) 214. Alternatively, database 216 may be part of or connecteddirectly to client 102 instead of communicating/obtaining theinformation from database 216 across network 202. When a developerencapsulates the business functionality into objects, the system may bereferred to as a component object model (COM) system. Accordingly, thescripts executing on web server 210 (and/or application 212) invoke COMobjects that implement the business logic. Further, server 206 mayutilize MICROSOFT'S™ Transaction Server (MTS) to access required datastored in database 216 via an interface such as ADO (Active DataObjects), OLE DB (Object Linking and Embedding DataBase), or ODBC (OpenDataBase Connectivity).

Generally, these components 206-216 all comprise logic and/or data thatis embodied in/or retrievable from device, medium, signal, or carrier,e.g., a data storage device, a data communications device, a remotecomputer or device coupled to the computer via a network or via anotherdata communications device, etc. Moreover, this logic and/or data, whenread, executed, and/or interpreted, results in the steps necessary toimplement and/or use the present invention being performed.

Although the term “user computer”, “client computer”, and/or “servercomputer” is referred to herein, it is understood that such computers102 and 206 may include portable devices such as cell phones, notebookcomputers, pocket computers, or any other device with suitableprocessing, communication, and input/output capability.

Of course, those skilled in the art will recognize that any combinationof the above components, or any number of different components,peripherals, and other devices, may be used with computers 102 and 206.

FIG. 3 is a block diagram that illustrates the components of a graphicscomputer program 110 according to the preferred embodiment of thepresent invention. There are three main components to the graphicsprogram 110, including: a Graphical User Interface (GUI) 300, an ImageEngine (IME) 302 including a parametric modeler 304 and an explicitmodeler 306, and a Database (DB) 308 for storing objects in files 310.

The Graphical User Interface 300 displays information to the user andprovides the functionality for the user's interaction with the graphicsprogram 310. The Image Engine 302 processes the Database 308 or files310 and delivers the resulting graphics to an output device. In thepreferred embodiment, the Image Engine 302 provides a completeapplication programming interface (API) that allows other computerprograms to interface to the graphics program 310 as needed. Theexplicit modeler 306 primarily creates geometry and topology for models.The parametric modeler 304, which interacts with the explicit modeler306, is a parametric feature-based solid modeler that integrates 2D and3D mechanical design tools, including parametric assembly modeling,surface modeling, 2D design, and associative drafting. The parametricmodeler 304 provides powerful solid-, surface-, and assembly-modelingfunctionality.

The Database 308 is comprised of two separate types of databases: (1) a3D database 312 known as the “world space” that stores 3D information;and (2) one or more 2D databases 314 known as the “virtual spaces” or“view ports” that stores 2D information derived from the 3D information.The 3D database 312 captures the design intent and behavior of acomponent in a model.

Software Environment

As described above, a model may be originally created in a parametricmodeler. The model may then be opened in an explicit modeler where theuser modifies the model. Such modifications are not part of the featurehistory because they are performed in a history-free modeler. When themodel is saved by the explicit modeler, two files may exist—the originalparametric history based model (e.g., an “.ipt” file) and a history freemodel (e.g., a “.dwg” model).

The history free model is opened in the parametric modeler. When opened,the parametric modeler recognizes that the model originated from aparametric model and opens the original file. An analysis is performedto determine the changes and how they relate to the model history. Basedon the analysis, edit options known as “treatments” are presented to theuser. The user may then determine which treatments to apply.

Accordingly, embodiments of the invention analyze the models, discover aset of differences, tie the differences back to the original featurehistory and present a list of “treatments” or edits that can be appliedto the parametric model features to affect the same results.

FIG. 4A illustrates an exemplary parametric, feature based, associativemodel that has been created in a parametric modeler in accordance withone or more embodiments of the invention. The feature history for themodel 402A is illustrated in window 404. The feature history indicatesvarious extrusions, a fillet, a chamfer, and a circular pattern. Oncecreated, an explicit modeler may be used to edit the model 402A. FIG. 4Billustrates the same model 402A of FIG. 4A after being modified in ahistory-free modeler (resulting in model 402B). The modifications in thehistory-free modeler were conducted without being aware of the featurehistory. As illustrated, various fillets have been removed, the width ofthe model has decreased, a pattern of holes has been modified, etc. Onceimported back in the parametric modeler, the problem is to find theseries of parameter and feature edits to the original model that willgenerate the same resulting solid model body (i.e., that was created inthe explicit modeler illustrated in FIG. 4B).

As described above, embodiments of the invention conduct an analysis toidentify the differences and prepare a list of “treatments” that can beapplied to the model to affect the same result as that shown in thehistory free model. FIG. 4C illustrates the parametric model 402A andthe history free model 402B with a list of feature centric changes or“treatments” illustrated in the Change Manager window 406. In window406, each change is identified along with the treatment that can be usedto achieve the change. The modifications are classified by the featurehistory. A set of edits, presented as “treatments,” are offered for eachfeature difference. The user can apply a treatment, ignore certainchanges or simply “apply all” to incorporate the changes back in theoriginal parametric model. Once or more of the treatments are selectedand applied, the parametric modeler will identify each of the changes inthe feature history of the parametric model itself. Accordingly, all ofthe changes can be edited at any time using the feature history list.Thus, the modifications made in the history-free modeler are essentiallyconverted into individual actions that can be identified in a featurehistory, where such actions are incorporated into the feature historyfor the original model.

Graphically, the differences may also be viewed. For example,faces/elements may high-light as the user moves a cursor (e.g., via acursor control device or mouse) over a particular element. Suchhighlighting may also be reflected in the Change Manager window 406. Forexample, when a user selects a particular text edit in the ChangeManager window 406, the corresponding change may be highlightedgraphically on the model itself. Similarly, if a user moves a cursorover a particular element in the graphic model 402A/402B, thecorresponding text change/treatment in window 406 may be highlighted.

The issue that arises is to how the changes to the model are trackedfrom the parametric modeler to the explicit modeler and back. Regardlessof whether in a parametric modeler or explicit modeler, a model consistsof geometry such as a boundary representation. In this regard, a solidmay be represented in a modeler by means of a boundary representation(b-rep) model. The boundary representation comprises a hierarchy oftopological objects that define the boundaries of successively simplerelements of the model. Embodiments of the invention may compare thedifferences between any two faces or b-reps.

To determine the differences, when a feature is created in either aparametric modeler or history free modeler, a tag is assigned/associatedwith the feature. Such a tag may be viewed as an attribute of theparticular feature or face that uniquely identifies the feature/face.Such tagging may be associated with any geometry, attribute or otherelement in a model (in both a parametric model and explicit model). Suchtags are utilized in both type of modelers. There are three differenttypes of edits that may be performed in an explicit modeler—(1)geometry/face/b-rep may be added; (2) a geometry/face/b-rep may bedeleted; and/or (3) a geometry/face/b-rep may be modified (e.g., a facemay be moved). Thus, if a new feature is created in an explicit modeler,a tag is created in the explicit modeler that is associated with the newface/feature.

When a model has been edited or created in an explicit modeler and isbrought back into a parametric modeler, the tags/attributes and theassociated location of the underlying geometry/features in the model402B are examined and compared to the tags and associated location inthe original model 402A. The comparison determines if tags are missing,the same, or if associated geometry/faces are in a different locationbetween the two models. Thus, if a face in the original model 402A hasthe same tag as a face in the modified model 402B and the associatedcontent/geometry is in the same location, it can be determined that sucha face has not been modified. Alternatively, if the tags exist in bothmodels 402A and 402B but the associated content/geometry is in adifferent location, a determination can be made that the content hasbeen moved to a new location. If tags are missing in either the originalmodel 402A or the explicit model 402B, a determination can be made thata face/geometry has been added/deleted during an edit.

It may be noted that the tags themselves may be implemented in a varietyof different formats (e.g., XML, object identifiers, etc.). Theparticular format in which they are represented in the models 402A and402B is not germane to the invention.

Once a determination has been made that a feature has been modified inthe explicit modeler, embodiments of the invention attempt to create aseries of treatments, for use in the parametric modeler, that will mostclosely/accurately resemble the modification. The steps for creating theseries of treatments progress from more to less robust operations. Inthis regard, embodiments will first try to modify an underlying actualfeature, then proceed to moving a face, and last attempt to use anextract/create face operation. Each of these steps will be describedbelow.

As a first step, embodiments of the invention attempt to modify theunderlying actual feature from the original parametric based model.Embodiments attempt to find a fully parametric edit to existingfaces/features/geometry that will match the edits performed in theexplicit modeler. Types of edits may include the modification ofparameters, a modification to the shape/position of sketch geometry orthe deletion of constraints from a sketch (e.g., the deletion of anequation that controls modification of a feature). Exemplary edits mayfurther modifications/additions/deletions of fillets, chamfers,extrusions, revolutions, patterns, and holes.

However, it may be physically impossible to find such a parametric edit.For example, such edits may be limited by constraints on theface/geometry. If it is not possible to make a change to existinggeometry, a move face command is attempted. For example, a face may bepulled off a certain distance in a fully parametric manner. Byattempting to move a face, the move will show up in the feature historyas a fully parametric feature. Thus, as an example, the first step wouldattempt to find a change to an extrusion to modify the extrusion to theright shape. If not possible, the second step would be to move the face.Such a move face command copies a face from the explicit modeler andconverts the face to a parametric associative face in the parametricmodeler. The parametric associative face is fully and directly editableusing parametric based commands.

If neither a face/geometry modification or move face command is able tomatch the new geometry (as modified in the explicit modeler), a newface/geometry may be created (e.g., using a variety of commands such asthe “sculpt command” from the Inventor™ 3D digital modeling applicationavailable from the assignee of the present invention). Such aface/geometry creation operation may copy the object from the explicitmodeler into the parametric modeler and then attempt to mold/sculpt theobject to create a solid model. Further, the face/geometry creationoperation may include/combine several independent commands/operations(e.g., a face deletion, surface trimming, splitting, stitching,sweeping, etc.). Such an object is often not parametrically based andrather than integrating into the existing feature history using existingfaces from the original parametric model, the new face/geometry creationcommand creates a new feature history.

Once the different sets of treatments have been identified per thisseries of steps, the different treatments are presented to the user. Thetreatments may further be color-coded (e.g., in the graphical imageshowing the comparison such as in FIG. 4C and/or in the textual featuretreatment list) to provide information to the user. For example,treatments may be indicated in red to show deleted features (e.g., afillet), green shading/coloring may be used to indicate newly-createdfeatures, blue shading/coloring may be used to identify old positions(e.g., from the original parametric model of FIG. 4A), and yellowshading/coloring may be used to indicate a new position (e.g., of theedited model in FIG. 4C).

Once the user has opted to apply a treatment, the treatment may affectother features of the model. For example, the feature affected by thetreatment may have downstream dependencies that depend on the feature(e.g., based on constraints). Accordingly, embodiments of the inventionreanalyze the new parametric model against the model in the explicitmodeler to determine/obtain a new list of changes/treatments. The aboveprocess of accepting treatments and reanalyzing are repeated until thechanges/treatments discovered are insignificant (e.g., small or beneatha threshold/level of tolerance) or non-existent. Such a threshold/levelof tolerance may be based on differences in pixels between the twomodels, parameter differences of a certain number, boundaryrepresentation (b-rep) differences, geometric differences, or a varietyof other factors.

Logical Flow

FIG. 5 is a flowchart illustrating the logical flow for managingmodifications to a solid between different modeling applications inaccordance with one or more embodiments of the invention. Each of thesteps (or a subset of the steps) may be performed using an add-in/add-onto a parametrically-based modeler.

At step 502, an original model created using a parametrically-basedmodeler is obtained in the parametrically-based modeler.

At step 504, a modified version of the original model is obtained in theparametrically based modeler. The modified version was edited/createdusing a history-free modeler.

At step 506, the original model and modified version areanalyzed/compared to determine one or more differences between them. Theanalyzing may compare feature tags assigned to each feature in theoriginal model to feature tags assigned/associated with each feature inthe modified version. Based on the comparison, the parametric modelermay determine if any feature from the original model or the modifiedversion has been added, removed, or modified.

At step 508, based on the differences, a set of one or moreparametric-based treatments are determined. The treatments, whenperformed on the original model, affect changes that produce aparametrically-driven version of (and/or that geometrically matches) themodified version. The treatments may be based on a three step process.In the first process, a fully parametric modification to a feature inthe original model is performed if possible. If not possible, a facefrom the modified version is copied to the parametric modeler.Thereafter, a parametric move face operation is performed on the copiedface, if possible. If the move face operation is not possible, a createnew face/geometry command is performed on the copied face.

At step 510, one or more of the treatments are selected. Each treatmentin the set is individually selectable for application to the originalmodel. To enable the selection, the set of treatments may be displayedin a text list.

At step 512, the selected treatments are applied to the original modelto produce the parametrically-driven version of the modified version.The applied treatments may be added to a feature history of theparametrically-driven version of the model. In addition, if the selectedtreatments have downstream dependencies, the determining step 508,selecting step 510, and applying step 512 are repeated (until no morechanges or few changes are needed). Further, the history of thetreatments that are presented to the user may be maintained stored.Alternatively, once a treatment is applied, the non-selected treatmentsmay be discarded.

Conclusion

This concludes the description of the preferred embodiment of theinvention. The following describes some alternative embodiments foraccomplishing the present invention. For example, any type of computer,such as a mainframe, minicomputer, or personal computer, or computerconfiguration, such as a timesharing mainframe, local area network, orstandalone personal computer, could be used with the present invention.

The foregoing description of the preferred embodiment of the inventionhas been presented for the purposes of illustration and description. Itis not intended to be exhaustive or to limit the invention to theprecise form disclosed. Many modifications and variations are possiblein light of the above teaching. It is intended that the scope of theinvention be limited not by this detailed description, but rather by theclaims appended hereto.

What is claimed is:
 1. A computer-implemented method for managingmodifications to a solid model between different modeling applications,comprising: obtaining an original model created using aparametrically-based modeler, in the parametrically-based modeler;obtaining, in the parametrically-based modeler, a modified version ofthe original model, wherein the modified version was edited using ahistory-free modeler; analyzing the original model and the modifiedversion of the original model to determine one or more differencesbetween the original model and the modified version of the originalmodel; determining, based on the one or more differences, a set of oneor more parametric-based treatments that, when performed on the originalmodel, affect changes that produce a parametrically-driven version ofthe modified version; selecting one or more of the parametric-basedtreatments, wherein each parametric-based treatment in the set isindividually selectable for application to the original model; andapplying the one or more selected parametric-based treatments to producethe parametrically-driven version of the modified version.
 2. Thecomputer-implemented method of claim 1, wherein the analyzing,determining, selecting, and applying steps are performed using an add-into the parametrically-based modeler.
 3. The computer-implemented methodof claim 1, wherein the set of one or more parametric-based treatmentsare displayed in a text list.
 4. The computer-implemented method ofclaim 1, wherein the applied one or more selected parametric-basedtreatments are added to a feature history of the parametrically-drivenversion of the modified version.
 5. The computer-implemented method ofclaim 1, wherein the analyzing comprises: comparing one or more featuretags assigned to each feature in the original model to one or morefeature tags assigned to each feature in the modified version; and basedon the comparison determining if any feature from the original model orthe modified version have been added, removed, or modified.
 6. Thecomputer-implemented method of claim 1, wherein the one or moreparametric-based treatments in the set comprise: determining thatperforming a fully parametric modification to a feature in the originalmodel is not possible; and copying a face of the modified version, andperforming a parametric move face operation on the copied face.
 7. Thecomputer-implemented method of claim 1, further comprising: determiningif the applied one or more selected parametric-based treatments havedownstream dependencies; and if there are downstream dependencies,repeating the steps of determining the set of one or moreparametric-based treatments, selecting one or more of theparametric-based treatments, and applying the one or more selectedparametric based treatments.
 8. An apparatus for managing modificationsto a solid model between different modeling applications in a computersystem comprising: (a) a computer having a memory; (b) aparametrically-based modeler executing on the computer, wherein theparametrically-based modeler is configured to: (i) obtain an originalmodel created using the parametrically-based modeler; (ii) obtain amodified version of the original model, wherein the modified version wasedited using a history-free modeler; (iii) analyze the original modeland the modified version of the original model to determine one or moredifferences between the original model and the modified version of theoriginal model; (iv) determine, based on the one or more differences, aset of one or more parametric-based treatments that, when performed onthe original model, affect changes that produce a parametrically-drivenversion of the modified version; (v) select one or more of theparametric-based treatments, wherein each parametric-based treatment inthe set is individually selectable for application to the originalmodel; and (vi) apply the one or more selected parametric-basedtreatments to produce the parametrically-driven version of the modifiedversion.
 9. The apparatus of claim 8, wherein the parametrically-basedmodeler further comprises an add-in that is configured to perform theanalyze, determine, select, and apply steps.
 10. The apparatus of claim8, wherein the set of one or more parametric-based treatments aredisplayed in a text list.
 11. The apparatus of claim 8, wherein theapplied one or more selected parametric-based treatments are added to afeature history of the parametrically-driven version of the modifiedversion.
 12. The apparatus of claim 8, wherein the parametrically-basedmodeler is configured to analyze by: comparing one or more feature tagsassigned to each feature in the original model to one or more featuretags assigned to each feature in the modified version; and based on thecomparison determining if any feature from the original model or themodified version have been added, removed, or modified.
 13. Theapparatus of claim 8, wherein the one or more parametric-basedtreatments in the set comprise: determing that performing a fullyparametric modification to a feature in the original model is notpossible; and copying a face of the modified version, and performing aparametric move face operation on the copied face.
 14. The apparatus ofclaim 8, wherein the parametrically-based modeler is further configuredto: determine if the applied one or more selected parametric-basedtreatments have downstream dependencies; and if there are downstreamdependencies, repeating the steps of determining the set of one or moreparametric-based treatments, selecting one or more of theparametric-based treatments, and applying the one or more selectedparametric based treatments.
 15. A non-transitory computer readablestorage medium encoded with computer program instructions which whenaccessed by a computer cause the computer to load the programinstructions to a memory therein creating a special purpose datastructure causing the computer to operate as a specially programmedcomputer, executing a method of managing modifications to a solid modelbetween different modeling applications, comprising: (a) obtaining, inthe specially programmed computer in a parametrically-based modeler, anoriginal model created using the parametrically-based modeler; (b)obtaining, in the specially programmed computer in theparametrically-based modeler, a modified version of the original model,wherein the modified version was edited using a history-free modeler;(c) analyzing, in the specially programmed computer, the original modeland the modified version of the original model to determine one or moredifferences between the original model and the modified version of theoriginal model; (d) determining, in the specially programmed computer,based on the one or more differences, a set of one or moreparametric-based treatments that, when performed on the original model,affect changes that produce a parametrically-driven version of themodified version; (e) selecting, in the specially programmed computer,one or more of the parametric-based treatments, wherein eachparametric-based treatment in the set is individually selectable forapplication to the original model; and (f) applying, in the speciallyprogrammed computer, the one or more selected parametric-basedtreatments to produce the parametrically-driven version of the modifiedversion.
 16. The non-transitory computer readable storage medium ofclaim 15, wherein the analyzing, determining, selecting, and applyingsteps are performed using an add-in to the parametrically-based modeler.17. The non-transitory computer readable storage medium of claim 15,wherein the set of one or more parametric-based treatments are displayedin a text list.
 18. The non-transitory computer readable storage mediumof claim 15, wherein the applied one or more selected parametric-basedtreatments are added to a feature history of the parametrically-drivenversion of the modified version.
 19. The non-transitory computerreadable storage medium of claim 15, wherein the analyzing comprises:comparing one or more feature tags assigned to each feature in theoriginal model to one or more feature tags assigned to each feature inthe modified version; and based on the comparison determining if anyfeature from the original model or the modified version have been added,removed, or modified.
 20. The non-transitory computer readable storagemedium of claim 15, wherein the one or more parametric-based treatmentsin the set comprise: determining that performing a fully parametricmodification to a feature in the original model is not possible; andcopying a face of the modified version, and performing a parametric moveface operation on the copied face.
 21. The non-transitory computerreadable storage medium of claim 15, further comprising: determining ifthe applied one or more selected parametric-based treatments havedownstream dependencies; and if there are downstream dependencies,repeating the steps of determining the set of one or moreparametric-based treatments, selecting one or more of theparametric-based treatments, and applying the one or more selectedparametric based treatments.